American Classic, Jim Carters, etc have both items. I just purchased the $54 windshield rubber from Steele because the cheap universal one I got from ACT wasn't very good. If you are referring to the material that holds the glass in the windshield frame it is sold by the foot and is called glass setting tape I believe is what I had ordered and it worked well.
I had purchased the window channel as well for the doors from American Classic Trucks when I rebuilt my doors. You will have to trim the channel to size when you do it.
here is the glass setting tape and the window channels..just look on the page for it:
ACT glass setting tape and channels.